They are born at around 12 days gestation. Notice that there hind legs and their tails isn't even separated from their bodies yet. They are born without placenta or umbilical cords. They are basically in an embryonic state.
When mom is ready to deliver, she will lick a path between her cloaca (yes, just like birds and reptiles have... opossums are one of our oldest mammals) and her marsupium (pouch).
The little joeys will crawl out of her cloaca and try to make their way to her pouch, only using those front tiny two hands. She can have up to 25 joeys, but she only has 13 nipples, so it's first come and first serve.
When the joey latches to the nipple, they stay latched on for a couple of months never unlatching, while they finish developing. Also, their mouths aren't fully developed at this stage. They can't open their mouths, they only have a small opening front center of the mouth, under the nose that they have to try and get mom's teat into.
Also when they are in mom's marsupium, she can tighten the muscles around the opening to make it water tight. Opossums are truly amazing creatures and so good for our ecosystem!
This post is from @naturesedgewildliferescue on FB.
